Antigen specific selection of antibodies (or other proteins) expressed on the surface of filamentous phage has previously been performed by affinity enrichment on columns or by panning. A valuable addition to this methodology would be to link receptor-ligand binding in a manner similar to clonal proliferation of lymphoid cells during an immune response. Recent studies indicate that it is indeed possible to link phage display of binding proteins directly to phage replication by genetically fusing the protein or antigen of interest to capsid protein gene3. Because this approach is unwieldy and inconveniently for most purposes the phase I goals of this proposal are to develop a general method to link phage displayed antibodies to phage replication. We will create a chimeric fusion protein linking streptavidin to the terminal 100 amino acids of the m13 gene3 protein. Next a test antigen turkey lysozyme will be biotinylated and finally we will test the capacity of this biotinylated antigen to rescue phage displaying an anti-turkey lysozyme scFv. These results will provide the basis for general methods to rapidly generate high affinity antibodies and other ligands for a diverse range of applications.